In general, a hydraulic excavator as a representative example of construction machines is provided with an automotive lower traveling structure, an upper revolving structure that is mounted on the lower traveling structure to be capable of revolving thereon and a working mechanism that is mounted on the upper revolving structure to be capable of tilting and lifting thereto.
A revolving frame as a base of the upper revolving structure is provided with a center frame that is positioned in an intermediate part in a left-right direction to extend in a front-rear direction, a plurality of extension beams that are arranged to extend in the left-right direction to be spaced in the front-rear direction from the center frame, left and right side frames that are arranged in the left-right direction across the center frame and are jointed to the respective extension beams to extend in the front-rear direction and a front side cab support frame that is disposed between a front end side of the left side frame and the center frame. On the other hand, the front side cab support frame of the revolving frame is regularly provided with two vibration isolating members (vibration isolating mounts), and the extension beam positioned in back of the front side cab support frame is regularly provided with two vibration isolating members (vibration isolating mounts).
A cab in which an operator gets is supported in a vibration isolating manner on a left front side of the revolving frame by the four vibration isolating members (Patent Document 1). At the traveling of the hydraulic excavator, each of the vibration isolating members alleviates vibrations to be transmitted to the cab through the revolving frame at working. In this way, the vibration isolating members are disposed, making it possible to improve ride comfort of an operator that controls the hydraulic excavator in the inside of the cab.
Here, the cab is arranged on an upper side of the revolving frame. Therefore, in some cases the cab is inclined or a gap between a lower end edge of the cab and the revolving frame is not made constant, depending upon a finish state at the time of manufacturing the revolving frame. Therefore, the hydraulic excavator adds spacers between the revolving frame and the vibration isolating members to perform a height adjustment of the cab.